Tired of all the hullabaloo when it comes to vacuum tubes? The 12AX7 is the most widely used tube today and is also one of the most important components in your tube amp's tone. The 12AX7 Sampler Set (includes 10 different tubes) allows you to try the most popular choices today and see for your self what the differences are. Preamp tubes can be easily swapped in and out of your amp without the need for biasing. We reserve the right to substitute any of these tubes with one of equal value based on availability.